Question

Two rods, one of iron and the other of aluminum, are heated to the same temperature difference. If the coefficient of expansion of iron rod is more than that of aluminum, then:

• A. the iron rod will expand less
• B. the iron rod will expand more
• C. both rods will expand equally
• D. the iron rod will not expand at all

Answer 1

The correct option is A the iron rod will expand less

Here given,

${\alpha }_1$=coefficient of expansion of iron

${\alpha }_2$=coefficient of expansion of Al

and ${\alpha }_1$>${\alpha }_2$

$\Delta t$ is same

Concept

$△L=L_0\alpha △t$

for iron

$△L_1=L_1{\alpha }_1△t$

for Al

$△L_2=L_2{\alpha }_2△t$

here since

${\alpha }_1>{\alpha }_2$

$△L_1$>$△L_2$

Iron rod will expand more.